Suzuki cross-coupling reaction over Pd-Schiff-base anchored mesoporous silica catalyst

A new hybrid catalyst has been prepared by tethering a palladium(II) Schiff-base complex via post-synthesis modification of mesoporous silica, MCM-41. The Schiff-base has been derived from o -vanillin and 3-[(2-aminoethylamino)propyl]trimethoxysilane (ATMS) which is chemically anchored on MCM-41 via silicon alkoxide route. The anchored Schiff-base imposed a stable planar coordination sphere on the central palladium ion. The catalyst has been characterized by elemental analysis, small angle X-ray diffraction, FT-IR, UV–vis, N 2 sorption study, transmission electron microscopy (TEM) studies and scanning electron microscopy (SEM) studies. X-ray and TEM measurement showed the mesoporosity of the catalyst. The activity of the catalyst has been assessed in the Suzuki C C cross coupling reaction using various phenyboronic acid in heterogeneous condition. High selectivity for the biaryl products containing both electron-donating and electron-withdrawing substituents, high turnover, mild reaction conditions and possibility of easy recycle makes the catalyst highly desirable to address the industrial needs and environmental concerns.